[004] HF Transformer Measurement and Modeling

How to measure and model high-frequency magnetics for switching power supplies. Essential steps for both custom-designed parts, or purchased components.

Power Supply Design Tips

This article points out some of the issues involved in designing, measuring, and modeling high-frequency magnetics for switching power supplies.

Despite efforts from some magnetics vendors to provide off-the-shelf components to power supply designers, almost all high-performance magnetics are custom. There are many deep and complex issues involved in the design of magnetics. I will try to cast some light on just a few of these issues.

Transformer Design Example

Figure 1 shows a simple 1:1 transformer. The transformer uses an ungapped EPC-25 core from TDK, made from PC-44 material. This transformer was designed for use in a 60 W forward converter with 36-60 V input and 12 V output.